> Basic building of the lego engine, plus
> Cylinder head with intake manifold, exhaust manifold
> Air filter on the intake side
> Muffler on the exhaust side
> Supercharger
> 2 Fans
> The big radiator with the necessary piping.
> Alternator
> the belt to drive all stuff

For this enigne, it can be configured as a DOHC or OHV. For my off-roader this is OHV
The engine as used in the 7 seater 4x4 off-roader